1. Field of the Invention
The present invention relates to a hinge device for a flap of a motor vehicle, the hinge device having a piston/cylinder unit, i.e., a pneumatic spring, which has a pressure tube and a piston displaceable in the pressure tube and provided with a piston rod, the piston/cylinder unit being arranged between a fixed structural part and a first flap which is pivotable about an axis of rotation and to which a second flap likewise pivotable about the axis of rotation can be connected releasably.
2. Description of the Related Art
A hinge device of this type is generally known from an opening arrangement for a panel of a counter. In this case, the panel is fastened to a first spar which is mounted rotatably, in each case by means of a journal, on two supporting arms forming a parallelogram. Furthermore, each of the supporting arms is mounted rotatably on a lower bearing spar by means of a further journal. Via additional journals, a pneumatically actuated piston is tied both to the lower bearing spar and to one of the supporting arms. An opening of the panel takes place in response to a pressure exerted by the piston, the supporting arms being pivoted and the first spar connected to the supporting arms being offset, together with the panel.
Furthermore, a hinge device with a pivotable openable tailgate of a motor vehicle is known, the tailgate having a rear window to be opened independently of the tailgate and likewise pivotably. A pneumatic spring is provided in each case for opening both the tailgate and the rear window. Such a hinge device is not only cost-intensive, but also has a complicated construction because of the numerous fastening elements required.
Another known hinge device with an arrangement corresponding to the abovementioned tailgate/rear-window version provides the use of torsion-spring elements for opening the tailgate and rear window. In addition to inconvenient operation, this hinge device is highly cost-intensive.